Determinación de trazas de emisores alfa en muestras biológicas y aplicación al cálculo de dosis internas

El objetivo de este trabajo es la determinación de radionucleidos emisores de partículas alfa en muestras biológicas. La importancia de esta determinación radica en que, los resultados obtenidos, sirven de base para calcular la dosis recibida por trabajadores profesionalmente expuestos a este tipo de radiación ionizante. La parte experimental del trabajo consistió en optimizar la metodología analítica para conseguir la separación de plutonio, americio y uranio en muestras de orinas y heces. Una vez aislados los radionucleidos de interés, las técnicas de medida utilizadas han sido la espectrometría alfa y fosforimetría inducida con láser, que permiten alcanzar límites de detección extremadamente bajos. La última parte del trabajo corresponde a la presentación de los resultados obtenidos en las intercomparaciones internacionales tanto analíticas como de aplicación de la metodología de cálculo de dosi

La apelación en la ley de enjuiciamiento civil

Partiendo del derecho a los recursos como una parte del derecho a la tutela judicial efectiva, nos centramos en este trabajo en el recurso de apelación, en el que como veremos, el tribunal superior conoce del asunto que ha sido resuelto en la primera instancia para corregir un defecto procesal o dictar una nueva resolución ajustada a Derecho. Es conocido como un recurso emblemático de nuestro ordenamiento jurídico, a través del cual, la persona que ha sufrido un perjuicio y que no ve satisfechas sus pretensiones iniciales o que piensa que la sentencia que se ha dictado no es conforme a derecho puede pedir un nuevo examen del asunto a ese tribunal superior. El recurso de apelación tiene una gran importancia práctica ya que como indica DE LA OLIVA SANTOS, es este recurso el que genera la segunda instancia y por lo tanto, no existiría segunda instancia sin apelación. Este doble grado de jurisdicción se fundamenta en la necesidad que tienen los ciudadanos que sufran un perjuicio a causa de una resolución judicial, de tener la posibilidad de solicitar un nuevo examen de su asunto, siempre que alguna de las partes lo solicite como una manifestación del principio dispositiv

Bibliometric mapping of the trends and contributions of scientific publications to risk and crisis communication regarding South America

Risk and crisis communication (R&CC) are crucial elements of managing vulnerability to big threats. This paper aims to explore the trends and contributions of scientific publications to R&CC about South America. Through the examination of 330 papers listed in the Web of Science database, the current study conducted a thorough overview between 1998 (oldest study) and 2021 (cut-off date) of bibliometric networks (keyword co-occurrence map, co-authorship maps, and author co-citation map) and multivariate statistical models (principal component analysis, compositional linear model). We address main communication factors, links between communication factors and countries, main academic cooperation networks, determinants of publication trends, and most cited authors. 28 R&CC factors were mapped and their relative importance to various hazards was examined. Most of these factors were intended to strengthen the communication system and increase risk knowledge of vulnerable people. Chile, Colombia, and Ecuador were mostly focused on strengthening R&CC. Brazil and Argentina were best represented with health and exposure to pollutants communication. Publications on R&CC are determined by the level of wealth, tourist arrivals, and the number of people affected by disasters. The compositional analysis revealed that the behavior of publications determinants could have opposite tendencies depending on the threats’ multidimensionality. To the best of our knowledge, this is the first R&CC study on South America to use CoDA in a bibliometric analysisPostprint (published version

A comparison of machine learning regression techniques for LiDAR-derived estimation of forest variables

Light Detection and Ranging (LiDAR) is a remote sensor able to extract three-dimensional information. Environmental models in forest areas have been benefited by the use of LiDAR-derived information in the last years. A multiple linear regression (MLR) with previous stepwise feature selection is the most common method in the literature to develop those models. MLR defines the relation between the set of field measurements and the statistics extracted from a LiDAR flight. Machine learning has emerged as a suitable tool to improve classic stepwise MLR results on LiDAR. Unfortunately, few studies have been proposed to compare the quality of the multiple machine learning approaches. This paper presents a comparison between the classic MLR-based methodology and regression techniques in machine learning (neural networks, support vector machines, nearest neighbour, ensembles such as random forests) with special emphasis on regression trees. The selected techniques are applied to real LiDAR data from two areas in the province of Lugo (Galizia, Spain). The results confirm that classic MLR is outperformed by machine learning techniques and concretely, our experiments suggest that Support Vector Regression with Gaussian kernels statistically outperforms the rest of the techniques.Ministerio de Ciencia y Tecnología TIN2011-28956-C02Junta de Andalucía P12- TIC-1728Universidad Pablo de Olavide APPB81309

Chiral Bifunctional Thioureas and Squaramides and Their Copolymers as Recoverable Organocatalysts. Stereoselective Synthesis of 2-Substituted 4-Amino-3-nitrobenzopyrans and 3-Functionalized 3,4-Diamino-4H-Chromenes

Producción CientíficaNovel styryl-substituted thioureas and squaramides were obtained in three steps from commercially available 4-hydroxy-3,5-dichloroaniline. These organocatalysts promote cascade reactions in high yields and excellent stereoselection. By using only a 5 mol % loading of catalyst, it is possible to obtain 2,3,4-trisubstituted benzopyrans by reaction of α-amido sulfones derived from salicyladehydes and nitrostyrenes or 2,3,4-trisubstituted 4H-chromenes by reaction of the same α-amido sulfones with (phenylsulfonyl)acetonitrile in excellent diastereo- and enantioselectivities. Two polymeric thioureas and squaramides were prepared by copolymerization of the best monomeric catalysts with styrene and divinylbenzene and used for the same transformations. These polymers behave also as excellent stereoselective catalysts that can be recovered and reused for five cycles.2019-11-112019-11-11Ministerio de Economía, Industria y Competitividad (Project FEDER-CTQ2014-59870-P)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Project FEDER-VA115P17

The ABCG2 protein in vitro transports the xenobiotic thiabendazole and increases the appearance of its residues in milk

[EN] Thiabendazole (2–(4–thiazolyl)benzimidazole, TBZ) is a broad–spectrum anthelmintic widely used in humans and cattle. It is also used as post–harvest agricultural fungicide, thus preserving crop quality and marketability (Hajikhani et al., 2024). Adverse effects after TBZ exposure including endocrine, nephrogenic, hepatogenic, teratogenic and neurological effects have been reported in mammals (Ekman et al., 2014). Etiological factors behind TBZ toxicity remain ambiguous; however, it has been hypothesized that it may be due to its bioactivation to 5OH–TBZ by the cytochrome P450 1A2 (CYP1A2) (Coulet et al., 1998a; Jamieson et al., 2011) (Fig. 1). Therefore, National and International Food Safety Authorities have established regulations for the usage of TBZ on food products setting maximum residue limits (MRLs) for the sum of TBZ and its metabolites in both agricultural and animal products ranging from 0.01 to 7 mg/kg depending on the product (European Food Safety Authority (EFSA) et al., 2021; U.S. Food and Drug Administration (FDA), 2021). Unfortunately, MRLs derived from pesticide use are equal to or higher than veterinary MRLs for all commodities, and the possible aggregated exposure from TBZ residues has not been studied, making it impossible to rule out an overexposure to TBZ through the food chain.SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Analysis of state tweets posted in 2020, during COVID-19, in South America within the framework of public health

Communication as an essential component for risk management receives renewed interest with the Sendai Framework for Disaster Risk Reduction 2015-2030 and the recent COVID-19 pandemic. The research aim was to analyze the most relevant factors of the communication issued by the Ministries of Health of eight Spanish-speaking countries in South America on Twitter, one of the most important social networks today. Particularly: a) an exploratory analysis of 40,082 tweets was carried out by detecting word communities; b) the communicational behavior was contrasted in the analyzed countries; c) the individual and collective communication behavior of these countries was analyzed in different stages of the pandemic in 2020; d) significant relationships between reported issues and the evolution of positive cases due to COVID-19 in 2020 were analyzed. Consequently, this study allowed the detection of 18 communication issues linked to the pandemic, such as the containment of the virus or communication in the face of deficiencies in the pandemic response system. In addition, it allowed to highlight some positive aspects such as early communication, communicational flexibility, inclusive communication or communication redundancy.Postprint (published version

Coadministration of ivermectin and abamectin affects milk pharmacokinetics of the antiparasitic clorsulon in Assaf sheep

[EN] In veterinary field, drug exposure during milk production in dairy cattle is considered a major health problem which concerns dairy consumers. The induced expression of the ABC transporter G2 (ABCG2) in the mammary gland during lactation plays a significant role in the active secretion of many compounds into milk. The main objective of this study was to determine the involvement of ABCG2 in the secretion into milk of the antiparasitic clorsulon in sheep as well as the possible effect of the coadministration of model ABCG2 inhibitors such as macrocyclic lactones on this process. Cells transduced with the ovine variant of ABCG2 were used to carry out in vitro transepithelial transport assays in which we showed that clorsulon is a substrate of the ovine transporter. In addition, ivermectin and abamectin significantly inhibited clorsulon transport mediated by ovine ABCG2. In vivo interactions were studied in Assaf sheep after coadministration of clorsulon (in DMSO, 2 mg/kg, s.c.) with ivermectin (Ivomec®, 0.2 mg/kg, s.c.) or abamectin (in DMSO, 0.2 mg/kg, s.c.). After ivermectin and abamectin treatment, no relevant statistically significant differences in plasma levels of clorsulon were reported between the experimental groups since there were no differences in the area under the plasma concentration-curve (AUC) between clorsulon treatment alone and coadministration with macrocyclic lactones. With regard to milk, total amount of clorsulon, as percentage of dose excreted, did not show statistically significant differences when macrocyclic lactones were coadministered. However, the AUC for clorsulon significantly decreased (p < 0.05) after coadministration with ivermectin (15.15 ± 3.17 μg h/mL) and abamectin (15.30 ± 3.25 μg h/mL) compared to control group (20.73 ± 4.97 μg h/mL). Moreover, milk parameters such as half- life (T1/2) and mean residence time (MRT) were significantly lower (p < 0.05) after coadministration of macrocyclic lactones. This research shows that the milk pharmacokinetics of clorsulon is affected by the coadministration of ABCG2 inhibitors, reducing drug persistence in milk.S

The partial volume effect in the quantification of 1H magnetic resonance spectroscopy in Alzheimer's disease and aging

[Abstract] 1H-MRS variability increases due to normal aging and also as a result of atrophy in grey and white matter caused by neurodegeneration. In this work, an automatic process was developed to integrate data from spectra and high-resolution anatomical images to quantify metabolites, taking into account tissue partial volumes within the voxel of interest avoiding additional spectra acquisitions required for partial volume correction. To evaluate this method, we use a cohort of 135 subjects (47 male and 88 female, aged between 57 and 99 years) classified into 4 groups: 38 healthy participants, 20 amnesic mild cognitive impairment patients, 22 multi-domain mild cognitive impairment patients, and 55 Alzheimer's disease patients. Our findings suggest that knowing the voxel composition of white and grey matter and cerebrospinal fluid is necessary to avoid partial volume variations in a single-voxel study and to decrease part of the variability found in metabolites quantification, particularly in those studies involving elder patients and neurodegenerative diseases. The proposed method facilitates the use of 1H-MRS techniques in statistical studies in Alzheimer's disease, because it provides more accurate quantitative measurements, reduces the inter-subject variability, and improves statistical results when performing group comparisons

Chiral Bifunctional Thioureas and Squaramides Grafted into Old Polymers of Intrinsic Microporosity for Novel Applications

Producción CientíficaWe have prepared different polymeric chiral bifunctional thioureas and squaramides by modification of the very well-known polymers of intrinsic microporosity (PIM), specifically PIM-1 and PIM-CO-1, to be used as recoverable organocatalysts. The installation of the chiral structures into the polymers has been done in two or three steps in high yields. The catalytic activity of the resulting materials has been proved in the stereoselective nitro-Michael addition and in a cascade process, which allows the synthesis of enantioenriched 4H-chromene derivatives. Squaramide II and thiourea III have been used in six cycles maintaining their activity. View Full-TextMinisterio de Economía, Industria y Competitividad - FEDER (Project CTQ2014-59870-P)Junta de Castilla y León - FEDER (programa de apoyo a proyectos de investigación - Ref. VA115P17, and VA149G18